Macionis, John J., author
Prentice-Hall, 2000
Buku Teks
Plummer, Kenneth, author
Rajawali, 2011
Buku Teks
Richardson, Niall, author
Routledge, 2014
Buku Teks
Neuman, Lawrence W., author
Pearson New International edition, 2014
Buku Teks
editor, Cat Sharpe
American Society for Training and Development Press, 2006
eBooks